WO2020078609A1

WO2020078609A1 - Refrigeration circuit with pressure equalization between multiple condensers

Info

Publication number: WO2020078609A1
Application number: PCT/EP2019/073431
Authority: WO
Inventors: Adrian ZIMMERMANN; Walter Zipp; Jörg Kirchhof; Andreas Inhoff
Original assignee: Ipetronik Gmbh & Co. Kg
Priority date: 2018-10-19
Filing date: 2019-09-03
Publication date: 2020-04-23
Also published as: DE102018125984A1; DE112019005204A5; CN113167508A; US20220363109A1

Abstract

The invention relates to a refrigeration circuit (1), in particular for use in a vehicle, preferably a motor vehicle, comprising: an air-conditioning compressor (2), a main condenser (4), at least one connectable condenser (5) and a switching means (3) that is designed to connect one or more of the connectable condensers (5) to the refrigeration circuit (1), a pressure adapting means (6) being designed to adapt an internal pressure of the at least one connectable condenser (5) to an internal pressure of the main condenser (4).

Description

REFRIGERATION CIRCUIT WITH PRESSURE COMPENSATION BETWEEN SEVERAL CAPACITORS

Modern air conditioning systems, especially in vehicles such as motor vehicles or trucks, are becoming more and more

Operating ranges of the cooling capacity required. These can be covered less and less with a fixed structural dimensioning of the heat exchanger. Furthermore, a fixed structural dimensioning of the heat exchangers can lead to disadvantages in terms of energy efficiency or the controllability of the air conditioning system.

In vehicles with a purely electric drive train in particular, there are many requirements for cooling the various components and systems. In addition to the usual cooling of the vehicle cabin, additional

There is a cooling requirement for the battery that supplies the drive train with energy or for the charging technology of the battery. As a result, significantly higher cooling capacities may be required at times. Such a battery can also be referred to as a drive train accumulator, since it is typically designed as a secondary battery and is intended to supply the drive train with energy.

Conventionally, the refrigerant circuit of such an air conditioning system of a purely electric vehicle only contains one condenser that is used continuously. The condenser is a heat exchanger in which the gaseous refrigerant compressed by an air conditioning compressor condenses with heat being emitted.On the dimensioning of this condenser, on the one hand it is dimensioned sufficiently large so that the cooling power required to cool the vehicle cabin and / or to cool the battery generated waste heat can be provided while driving. Too big

However, dimensioning of the condenser leads to an energetically inefficient operation of the refrigerant circuit, as a result of which the battery has to provide more energy for operating the refrigerant circuit. This would ultimately significantly reduce the maximum range of the purely electric vehicle.

The required, wide performance range of the air conditioning compressor can be regulated by the speed, the pressure conditions and / or the mass flow of the refrigerant flowing through the air conditioning compressor. In the case of heat exchangers, such as a condenser, the area which can be used in terms of energy efficiency can only be used by arranging several, preferably expand capacitors of different dimensions, between which you can switch using suitable valves.

Frequent switching between the different capacitors may be necessary, especially when charging the battery while driving,

For example, the battery can be charged while driving

Recuperation happen, i.e. a recovery of recovered

Braking energy. Charging the battery while driving can also be made possible, for example, by inductive charging. Becomes a

Driving a section of the route in which the battery can be charged, a powerful capacitor is connected to a low-dimension, permanently operated capacitor in order to provide a corresponding cooling capacity for waste heat generated during charging. Will this

If you leave the section of the route, the powerful heat exchanger is deactivated.

In particular, frequent charging between the heat exchangers can be expected when charging the powertrain accumulator during ferry operation, since not every route is equipped with charging technology throughout. When entering a section with charging technology, the powerful heat exchanger switches on and cools away the high waste heat that is generated during charging. The powerful heat exchanger is deactivated when you leave the section or route section with charging technology.

Switching between two different condensers that are not permanently flowed through creates pressure surges in the gas dynamics of the refrigerant. These pressure surges can lead to noise that is disturbing comfort. Furthermore, the durability of the components of the refrigerant circuit and / or the air conditioning system can be significantly impaired. In addition, the refrigerant can be adversely shifted to temporarily unused

Areas of the refrigerant circuit come so that the refrigerant in the

Cycle of the refrigerant circuit cannot be used actively. This significantly reduces the energy efficiency of the refrigerant circuit.

From the prior art so far it can be seen that there is still no satisfactory technical solution to the disadvantages described above. It is therefore the object of the invention to provide a refrigerant circuit which, on the one hand, has cooling capacities as wide as possible

Operating ranges enabled and on the other hand dampens and / or insulates pressure surges in the gas dynamics of the refrigerant, and / or even completely prevented.

The object is achieved in particular by a refrigerant circuit according to claim 1, a method for operating the refrigerant circuit according to claim 22 and a vehicle according to claim 25.

According to a first aspect of the invention, the object is achieved in particular by a refrigerant circuit, in particular for use in a vehicle, preferably a motor vehicle, comprising; an air conditioning compressor, a main condenser, at least one switchable (or, optionally,

switchable) capacitor, as well as a switching means, which is designed to

connect one or more of the connectable condensers to the refrigerant circuit, wherein a pressure adjustment means is designed to one

Internal pressure of the at least one connectable capacitor to one

Adjust (or approximate) the internal pressure of the main condenser.

In particular, the main capacitor is operated permanently actively and the or the connectable capacitors are during normal operation of the

Refrigerant deactivated, the main condenser is dimensioned in such a way that it is adapted to the required cooling capacity in normal operation. As soon as more cooling capacity is required, the switchable condenser (s) can be switched on by the switching means. The one or more previously deactivated switchable capacitors, however, normally have a lower internal pressure than the active main capacitor. In particular, switching on without equalizing the internal pressure of the switchable condenser (s) can result in a pressure surge due to jerky inflow of the refrigerant into the switchable condenser (s). There is consequently a relationship between an internal pressure difference of the main condenser with respect to the condenser (s) that can be switched on, by this

If the internal pressure difference is kept as small as possible before switching on or if the internal pressures are completely adjusted to one another, a pressure surge that occurs when switching on can be minimized. In particular, the adjustment can even ensure that pressure surges are completely avoided or at least reduced (significantly). If the internal pressure in one of the deactivated condensers should rise too high due to the pressure equalization means, suitable non-return valves can be used to connect the condensers

downstream, prevent a continuous pressure increase from taking place.

A refrigeration machine is in particular a refrigerant circuit

understood, in which a refrigerant is moved in a circuit. The refrigerant preferably experiences different ones in succession

Physical state changes, The initially gaseous refrigerant is compressed in an air conditioning compressor. The air conditioning compressor is followed by a condenser in which the refrigerant condenses with the release of heat.

The liquefied refrigerant is then expanded via a throttle due to a change in pressure, which is designed, for example, as an expansion valve or an expansion capillary. In a downstream evaporator, the refrigerant evaporates while absorbing heat, which removes thermal energy from the evaporator. The refrigerant circuit is now again

pass through, so that a compression of the gaseous refrigerant in the

Air conditioning compressor takes place. Typical application goals of a

The refrigerant circuit can consist in the provision of cooling capacity and / or thermal capacity (heat pump operation). In particular

Applications of, for example, electrically powered motor vehicles, the simultaneous need for cooling capacity (for cooling the inverter and accumulator) and for heating capacity (for heating the vehicle cabin) can occur during the quick charging of the drive train accumulator in winter.

Under an evaporator and a condenser is generally one

Understand heat exchanger (a heat exchanger).

The respective heat exchanger can be configured as a gas cooler.

A plurality of heat exchangers (connected in parallel and / or in series) can form one heat exchanger unit.

A plurality of capacitors (connected in parallel and / or in series) can form a capacitor unit. Several evaporators (connected in parallel and / or in series) can form one evaporator unit.

The refrigerant circuit can be configured so that air and / or water and / or coolant or media can flow through.

An adjustment or approximation of the respective pressure, in particular internal pressure, is to be understood in particular to mean that a pressure difference of at least 50%, preferably at least 90%, is smaller compared to a (hypothetical case) in which the (respective) pressure adjustment means is not provided is or is inactive.

In particular, any common refrigerant, but also special refrigerants such as C02 (R744) can be used as the refrigerant. Furthermore, the devices and methods according to the invention can be applied to single- and multi-phase fluids or fluid mixtures outside of refrigeration technology, for example in hydraulics or pneumatics.

In particular, a rotary piston compressor,

Scroll compressors, reciprocating compressors, screw compressors or turbocompressors are understood, the compression performance during operation via its speed and / or via the position of a swash plate and / or

Cylinder deactivation can be controlled or regulated.

In particular, the main condenser is to be understood as a heat exchanger which is dimensioned in such a way that it guarantees optimum cooling performance during normal operation. In normal operation, the main capacitor is preferably permanently active. The dimensioning of a condenser relates to the spatial extent of the condenser. At least essentially there is a proportionality between cooling capacity and size of an inner surface of the condenser. A connectable condenser is another, preferably differently dimensioned, condenser, which can be connected to the refrigerant circuit by means of a switchover means.

A switchover means can be, for example, a switchover valve that can switch a fluid stream present at an inlet to a first outlet or to a second outlet. In addition, it is also possible to implement this functionality by using two individual valves. In addition, intermediate states are also possible in which the fluid flow present at the input can be divided proportionally between the outputs of the changeover valve.

In particular, switching on can also be understood to mean switching, so that after switching on the main capacitor is deactivated and the switchable capacitor (s) is activated. It is also possible that from a large number of connectable capacitors only certain connectable ones

Capacitors are switched on while others are switchable

Capacitors remain deactivated. It is also possible that one of the connectable capacitors is permanently active during normal operation and the main capacitor is switched on.

Furthermore, the pressure adjustment means is particularly suitable for heating the connectable capacitor (s) and / or the main capacitor, as a result of which the internal pressures can be adjusted (approximating) easily and inexpensively.

In a preferred embodiment, the pressure adjustment means comprises an electrical heater, which is in particular designed to be switched on and off and / or can be controlled and / or regulated. The electric heater is particularly suitable for being precisely controlled or regulated, as a result of which the internal pressures can be adjusted as quickly and efficiently as possible. Furthermore, an electric heater or, respectively, an electric heater can easily be placed in the switchable capacitors and / or the

Integrate main capacitor. An electric heater can also be attached externally instead of being fully integrated into the capacitor. Furthermore, several locally activated heaters can be placed on / in components or on / in lines at any point in the refrigeration circuit.

The pressure adjustment means is preferably suitable for flowing one or more of the capacitors that can be switched on with a waste heat from the

Main condenser to heat. This makes it possible to use the waste heat from the main condenser. The refrigerant circuit can thus be optimized in terms of energy efficiency. Alternatively, the pressure adjustment means is suitable for passing one or more of the connectable capacitors

To heat the inflow with preheated fresh air.

In a preferred embodiment, the refrigerant circuit also has at least one evaporator, at least one additional one

Pressure change means is arranged before, within and / or after the evaporator with respect to a flow direction of the refrigerant circuit, which

is designed in particular to adapt an internal pressure of the evaporator (s).

In particular, pressure change means can be understood to mean a pressure adjustment means of the above type. The pressure change means can by

Inflow can be heated with waste heat, for example from the main condenser, whereby a change in pressure of the internal pressure is achieved. Of

Furthermore, pressure change means can comprise electrical heaters, which are in particular designed to be switched on and off and / or can be controlled and / or regulated.

As a result, disturbing noise developments (such as

Hissing noises) avoided or at least reduced, which can occur due to non-stationary phase transitions and / or sloshing liquid refrigerants.

In addition, icing of the evaporator can be avoided, so that a cooling capacity can be increased in a chiller. As a result, higher speeds of the

(electronic) refrigerant compressor (eKMV) and a larger one

Mass flow share that flows through the chiller possible.

Furthermore, it is in particular avoided that there are refrigerant displacements at different points in the refrigerant circuit, for example in the

Evaporator can come.

It is preferred that at least a further subsection of the

Refrigerant circuit (such as a second refrigerant compressor or a second evaporator) can be temporarily disconnected and connected to the refrigerant circuit, in particular the at least one further section being provided with at least one further pressure equalizer, which are preferably designed to have an internal pressure of several sections

to match and / or approximate to one another and / or to the internal pressure of the main capacitor and / or the connectable capacitor. This can

Reduce pressure gradients during switching operations between sections of the refrigeration circuit or avoid them if possible.

According to the invention, further subsections can be understood, for example, to mean a second refrigerant compressor which can be connected in parallel or in series with the first refrigerant compressor with corresponding switching means. Furthermore, broad sections can also be understood, for example, to mean that a second evaporator, which can be connected in parallel or in series with the first evaporator, with corresponding switching means.

The refrigerant circuit preferably also has at least one throttle element, which is in particular controllable and / or regulatable, the or the throttle elements preferably before, within and / or after the evaporator and / or the main condenser and / or the connectable condenser with respect to the flow direction of the Refrigerant circuit is or are arranged. In this way, phenomena coupled with gas dynamics and vibroacoustics (such as hissing, rippling) and / or icing of the or the

Evaporators are avoided. In addition, increases in performance for cooling and heating purposes can be achieved by increasing the pressure and temperature level on the chiller, evaporator, condenser and / or gas cooler, which enables a higher eKMV speed and a larger one

Mass flow share that flows through the chiller become possible.

Furthermore, in particular a heat exchanger or phase separator is arranged in front of the air conditioning compressor with respect to the flow direction of the refrigerant circuit, as a result of which, in particular in the case of fluorine-based refrigerants, it can be avoided that the compressor sucks in liquid.

In particular, the pressure balancing means can additionally have a pressure balancing capillary or can only be one by means of which the main condenser can be fluidly connected to one or more of the connectable capacitors and / or the connectable capacitors can be connected to one another. Through the

Pressure adjustment capillaries always have an identical static internal pressure in the main condenser and in the condenser (s) that can be switched on. The resulting refrigerant mass flow means that an insufficient amount of refrigerant is avoided both in the main condenser and in the condenser (s) that can be connected. In order to prevent condensation of the refrigerant flowing through the pressure equalization capillary, the condenser (s) that can be connected are not cooled in normal operation. This can preferably be achieved by supplying heat and / or by blocking supply air, for example by louvre flaps. This makes it particularly easy to adjust the internal pressures

can be realized inexpensively.

The pressure adjustment capillary preferably has a controllable shut-off valve and / or a check valve, with which it is possible to have a regulated one

Adjustment of the internal pressures through the inexpensive pressure adjustment capillary.

In a particularly preferred embodiment, the switchover means, in particular in combination with the pressure adjustment means, is arranged in such a way that the switchable capacitor (s) can be connected in series with the main capacitor, the switchover means, especially in combination with the pressure adjustment means, preferably upstream with respect to the

Main capacitor and the one or more connectable capacitors is arranged. This enables a targeted connection of the switchable switch or switches

Capacitors. The main capacitor is permanently active in this circuit variant.

Alternatively, the switching means, in particular in combination with the

Pressure adjustment means, arranged such that the switchable one or more

Capacitors can be / are connected in parallel to the main capacitor, the switchover means, in particular in combination with the pressure equalization means, preferably being arranged upstream of the main capacitor and the switchable capacitor (s). A parallel connection of the main capacitor and the switchable capacitor or capacitors results in further circuitry possibilities. A parallel connection makes it possible, for example, to switch on the capacitor or capacitors

switch on while the main capacitor can be relieved or deactivated. In addition, a finer division of the switching states can be carried out. For example, a main capacitor, which is dimensioned small, and a switchable capacitor, which is dimensioned larger than the main capacitor, by a parallel connection, in three

Switching states are switched, in a first switching state

Main capacitor active and the switchable capacitor deactivated. In a second switching state, the switchable capacitor is active and the

Main capacitor is deactivated. And finally, in a third

Switching state of the main capacitor and the switchable capacitor active. The different dimensions of the main condenser and the connectable condenser thus result in three different cooling line levels with which the refrigerant circuit can be operated.

In particular, the pressure adjustment means is controlled and / or regulated by a control or regulating unit, the main capacitor and the connectable capacitor (s) each having pressure sensors which are designed to send measurement data from the pressure sensors to the control or regulating unit. In particular, the pressure sensors deliver measurement data about the internal pressures of the main condenser and the condensers that can be switched on. These measurement data are preferably sent to the control unit, which makes it possible to reliably relate the internal pressure in the condensator or condensers to the internal pressure of the main condenser regulate. A proportional-integral controller (PI controller) or also a proportional-integral-differential controller (PID controller) can function as a control or regulating unit. In this context, however, a plurality of control or regulating devices which are assigned to the individual main capacitor or the at least one individual connectable capacitors can also be understood as a control or regulating unit. The individual control devices are preferably connected to one another and to the respective pressure sensors via a bus communication system.

As an alternative, pressure sensors can also be installed in the supply lines of the main capacitor and the switchable capacitor or capacitors

are designed to send measurement data from the pressure sensors to the control unit. By attaching the pressure sensors in the respective supply lines, the main capacitor and the switchable capacitor (s) remain cheap and easy to manufacture, since the pressure sensors do not have to be integrated in the capacitors.

In particular, the pressure adjustment means can vary a

Have waste heat flow in a waste air flow of the main condenser and / or in or in the connectable capacitors, wherein in particular the means for varying the waste heat flow are pivotable louvre flaps.

This embodiment is particularly inexpensive.

The switchover means can preferably be designed as a switchover valve, in particular a 3/2-way switchover valve, which, in addition to an open and a closed switching state, enables a partly open switching state in particular. As a result, the internal pressures can be adjusted directly by the switching means without the need for a separate capillary before the main mass flow is released.

Furthermore, the switching means can be designed as a multi-way switching valve. This means that as an m / n-way switch valve, it switches m inputs to n outputs.

It is preferred that the changeover valve has a pressure equalization capillary with which a fluid connection can be established between a first outlet line and a second outlet line of the changeover valve. In particular, the pressure adjustment capillary can be at least partially integrated within the changeover valve.

This can compensate for pressure gradients between the

Output strands of the changeover valve can be reached with the aid of a pilot fluid flow leading ahead of time, as a result of which pressure surges are avoided.

In particular, the pressure adjustment capillary has a valve which is suitable for opening and closing the pressure adjustment capillary, as a result of which the

leading pilot fluid flow can be adjusted. The pressure adjustment capillary is preferably permanently open.

It is preferred that the changeover valve has capillary bores in a stator and / or a rotor of the changeover valve, as a result of which a fixed time sequence can be achieved in which a pilot fluid flow leads a main fluid flow ahead of time during each changeover process.

The above object is achieved in particular by a method for operating a refrigerant circuit, the main condenser being operated continuously actively and before and / or during connection of one or more of the connectable capacitors, the internal pressure of the connectable one or more

Capacitors is adjusted to the internal pressure of the main condenser (or is approximated to this).

It is preferred that when switching on one or more of the connectable capacitors, first a pilot fluid flow through the pressure adjustment capillary and / or the capillary bores of the changeover valve to adjust the

Internal pressure of the switchable capacitor (s) flows to the internal pressure of the main capacitor. As a result, the internal pressure of the connectable condenser (s) and / or of strands connected to the connectable condenser (s) can be adjusted before a main fluid flow is switched over.

The capillary can optionally be connected outside the 3/2-way valve. As a result, the capillary can also be coupled to a position in the refrigerant circuit which carries liquid refrigerant. This can be done, for example, on the liquid line downstream of the condenser.

In particular, a speed and / or a mass flow of the air conditioning compressor can be determined before and / or during connection, the air conditioning compressor being controlled such that when the speed and / or the mass flow is a very small value, which is preferably zero the speed and / or the mass flow to this very small value, the

is preferably equal to zero, is regulated. Such a control can prevent the air conditioning compressor from being caused by a pressure drop between an internal pressure of the air conditioning compressor and the internal pressure of the

Main capacitor and / or the switchable capacitor (s) or a fluid flow resulting from the pressure drop can be moved or rotated with it. In particular, a very small value of the rotational speed can be understood to mean a value which is less than 0.5 rpm, preferably less than 0.1 rpm or particularly preferably less than 0.01 rpm. A very small value of the mass flow can be understood to mean a value which is less than 2.5 g / s, preferably less than Ig / s, or in particular less than 0.01 g / s.

The above object is further achieved in particular by a vehicle, in particular a motor vehicle, which comprises a refrigerant circuit of the above type, which is operated in particular by a method of the above type. The vehicle is preferably an electric vehicle or a hybrid vehicle, the vehicle having a drive train accumulator. In particular when the drive train accumulator is being charged while the vehicle is running, frequent switching between the condensers of the refrigerant circuit is to be expected, since not every route is continuously equipped with charging technology. When entering a section with charging technology, the powerful capacitor switches on and cools away a lot of waste heat that is generated during charging. When you leave the section with charging technology, the powerful capacitor is deactivated again. In this scenario, the application of the present invention is particularly advantageous.

Further embodiments result from the subclaims.

The invention is described below on the basis of exemplary embodiments, which are explained in more detail with reference to the figures. Here shows:

Fig. 1 is a circuit diagram of a first embodiment of the

refrigerant circuit according to the invention;

2 shows a circuit diagram of a second embodiment of the refrigerant circuit according to the invention;

3 shows a circuit diagram of a further embodiment of the refrigerant circuit according to the invention;

4 shows a circuit diagram of a further embodiment of the refrigerant circuit according to the invention;

5 shows a circuit diagram of a further embodiment of the refrigerant circuit according to the invention;

6 shows a circuit diagram of a further embodiment of the refrigerant circuit according to the invention;

7 shows a circuit diagram of a further embodiment of the refrigerant circuit according to the invention;

8 shows a circuit diagram of a further embodiment of the refrigerant circuit according to the invention;

9 shows a circuit diagram of a further embodiment of the refrigerant circuit according to the invention;

10 shows a circuit diagram of a further embodiment of the refrigerant circuit according to the invention;

11 shows a circuit diagram of a further embodiment of the refrigerant circuit according to the invention;

12 shows a circuit diagram of a further embodiment of the refrigerant circuit according to the invention;

13A schematic detailed view of an embodiment of a 3/2

Directional switching valve in a first switching state;

13B shows a schematic detailed view of an exemplary embodiment of a 3/2-way changeover valve in a second changeover state;

13C shows a schematic detailed view of an exemplary embodiment of a 3/2-way changeover valve in a third changeover state;

14A shows a schematic detailed view of an exemplary embodiment of a 3/2-way changeover valve in a first changeover state;

14B shows a schematic detailed view of an exemplary embodiment of a 3/2-way changeover valve in a second changeover state; such as

14C shows a schematic detailed view of an exemplary embodiment of a 3/2-way changeover valve in a third changeover state;

1 shows a circuit diagram of a first embodiment of the refrigerant circuit according to the invention. The refrigerant circuit 1 shown comprises the following components: an air conditioning compressor 2, a downstream precooler 10, a downstream changeover valve 3, a main condenser 4 and a connectable condenser 5, which can be connected in series, and two parallel expansion valves 8, each with a downstream evaporator 7. Between the switching means 3 and the

Main capacitor 4, a check valve 9 is arranged and a further check valve is arranged between the main capacitor 4 and the connectable capacitor 5. The individual components are through

Refrigerant lines connected.

Furthermore, the main condenser 4 and the connectable condenser 5 each comprise a pressure sensor 12. The connectable condenser 5 comprises a pressure equalization means 6, which in the embodiment shown as one

controllable or regulable, electric heating is executed. In the

The embodiment shown also includes the main capacitor 4

Pressure adjustment means 8, which is also designed as a controllable or adjustable electrical heater 6. In addition, a control or regulating unit 11 is shown in FIG. 1, which is suitable for measuring data of the

To receive pressure sensors 12 and to control or regulate the controllable or regulatable electrical heaters in the connectable capacitor 5 and / or in the main capacitor 4 on the basis of the received measurement data.

The rectangles depicted in FIG. 1 between the components of the refrigerant circuit 1 shown indicate locations in the refrigerant circuit 1 at which further modifications to the refrigerant circuit 1 can be made. These further modifications make it possible to further reduce the amplitude of the gas pressure surges that may occur or their vibroacoustic effects.

For example, one of these modifications can consist of a muffler, which is a component that is initially an expanding, double

Cross-sectional jump and then a narrowing double

Cross-sectional jump. Furthermore, the modifications can include Helmholtz resonators or fluid silencers in the form of compressible bodies within the refrigerant line. Fluid silencers in the form of a secondary volume coupled to the line (compressor protection) are also conceivable. Hose components with mechanically flexible elastomer components or adjustable bypass lines between the inlet and outlet of the changeover valve are also possible. Active counter-sounds can also be generated

Components are used that use the pressure surge by means of destructive

Can cancel interference. Material accumulations in the walls of the refrigerant lines and / or in fluid-carrying components can also be carried out as further modifications. Barrier compounds on the refrigerant lines and / or on fluid-carrying components are also conceivable.

FIG. 2 shows a circuit diagram of a further embodiment of the refrigerant circuit 1 according to the invention. In addition to the embodiment shown in Fig.

1 is shown, the switching valve 3 by two individual

Changeover valves 3 executed,

3 shows a further embodiment of the invention

Refrigerant circuit 1. This is a series connection between the main condenser 4 and the connectable condenser 5, similar to that shown in FIG. 1, but here a pressure equalization capillary 6 serves as

Pressure balancing means 6. In this embodiment, the switching means 3 is designed as a single switching valve 3 with one input and two outputs, between which it is possible to switch.

4 shows a further embodiment of the invention

Refrigerant circuit 1 shown. The illustrated refrigerant circuit 1 also comprises a series connection between the main condenser 4 and the connectable condenser 5, similar to that shown in FIG. 1. In this

Embodiment, however, serves as a pressure adjustment capillary 6

Pressure adjustment means 6 instead of an electric heater 6 as in the

Embodiment shown in Fig. 1. In addition to the embodiment shown in FIG. 3, the changeover valve 3 is implemented here by two individual changeover valves 3,

5 shows a further embodiment of the invention

Refrigerant circuit 1. The illustrated refrigerant circuit 1 also comprises a series connection between the main condenser 4 and the connectable condenser 5, similar to that shown in FIG. 1. In this embodiment, in addition to the controllable or controllable electric heater

Pressure adjustment capillary 6 as pressure adjustment means 6. In this embodiment, the switching means 3 is designed as a single switching valve 3 with one input and two outputs, between which it is possible to switch.

The embodiment of the invention shown in FIG. 6

Refrigerant circuit 1, like the embodiment shown above, also shows a series connection between the main condenser 4 and a connectable condenser 5

Heaters 6 together with a pressure adjustment capillary 6 used as pressure adjustment means 6. Only the switching means 3 is different from the previous one

Embodiment, in this embodiment by two separate changeover valves

3 executed,

Fig. 7 shows a circuit diagram of a further embodiment of the

refrigerant circuit 1 according to the invention, that shown in FIG. 7

Refrigerant circuit 1 forms a parallel arrangement of the main condenser 4 and the connectable condenser 5,

The parallel arrangement of the main capacitor 4 and the switchable

Condenser 5 requires that a check valve 9 is arranged downstream of the main condenser 4 and the connectable condenser 5, since otherwise refrigerant, which has already passed the active condenser (such as the main condenser 4), into the deactivated condenser (such as the connectable one) Capacitor 5) flows or is pressed into it. This would remove the refrigerant from the active refrigerant circuit, so that the cooling capacity of the refrigerant circuit would decrease.

This can be prevented by the appropriate arrangement of the check valves 9.

In particular, it is in the embodiment shown by the

Parallel arrangement of the main capacitor 4 and the switchable capacitor 5 enables, which can be switched between the main capacitor 4 and the switchable capacitor 5. In this way, for example, the connectable capacitor 5 can initially be active and the main capacitor deactivated. Switching can now take place in such a way that the main capacitor

4 is operated actively and the connectable capacitor 5 is deactivated.

In addition, it would also be possible to actively operate both the main capacitor 4 and the switchable capacitor 5.

8 shows a further embodiment of the invention

Refrigerant circuit 1 shown. The refrigerant circuit 1 shown here, like the refrigerant circuit shown in FIG. 7, is also a parallel arrangement

between the main capacitor 4 and the switchable capacitor 5. The difference between the embodiment shown in FIG. 7 is that the switchover means 3 is implemented by two switchover valves 3.

9 shows a further embodiment of the invention

Refrigerant circuit 1 shown. The illustrated embodiment is, as previously shown in FIGS. 7 and 8, a parallel connection between the

Main capacitor 4 and the switchable capacitor 5. In contrast to the embodiment shown above, here the internal pressure of both

Capacitors adjusted by a pressure adjustment capillary 6. An electric heater 6 is not provided in this embodiment.

The embodiment shown in FIG. 10 is also a parallel connection of the capacitors. Here, too, a pressure adjustment capillary 6 serves as

Pressure adjustment means 6. The switching means 3 is shown in FIG. 10 by two separate

Changeover valves 3 realized.

11 shows a further embodiment of the invention

Refrigerant circuit 1 shown, in which there is a parallel connection between the main condenser 4 and the connectable condenser 5. In this embodiment, both electric heaters 6 and 6 are used

Pressure adjustment capillary 6 as pressure adjustment means 6. The picture

Switching means is as a switching valve 3 with one input and two

Exits.

Finally, FIG. 12 shows a refrigerant circuit 1 according to the invention, which essentially corresponds to the refrigerant circuit 1 shown in FIG. 11.

In this embodiment, however, the switching means 3 is implemented by two separate switching valves 3.

13A shows a schematic detailed view of an exemplary embodiment of a 3/2-way changeover valve 3 in a first changeover state. The 3/2-way switch valve 3 has an inlet line 31, a first one

Outlet line 32 and a second outlet line 33. Furthermore, that points

3/2-way changeover valve 3 has a changeover valve capillary 34, which in this exemplary embodiment is completely accommodated and / or integrated in a changeover valve housing 36.

In addition, the 3/2-way changeover valve 3 comprises a changeover valve rotor 35 which can be moved such that a main fluid stream HF5 can flow through the inlet line 31 via the changeover valve rotor 35 into the first outlet line 32. In Fig. 13A, the main fluid stream HFS flows through the

Inlet line 31 via the changeover valve rotor 35 into the first outlet line 32. The depicted state is referred to as the first changeover state,

13B shows the exemplary embodiment of the 3/2-way changeover valve 3 shown in FIG. 13A in a second changeover state. The changeover valve rotor 35 is in a position in which the main fluid flow HFS continues through the inlet line 31 via the changeover valve rotor 35 in the first

Outlet line 32 flows. In the second switching state, however, the switching valve rotor 35 is in a position in which the

Changeover valve capillary 34 opens to the main fluid flow HFS, so that a pilot fluid flow PFS can flow through the changeover valve capillary 34,

As a result, HFS occurs before the main fluid flow is switched

Pressure compensation by the pilot fluid flow via the changeover valve capillary 34 instead.

FIG. 13C shows the exemplary embodiment of the 3/2-way switch valve 3 shown in FIGS. 13A and 13B in a third switchover state. In this state, the main fluid flow HFS flows through the inlet line 31 via the changeover valve rotor 35 into the second outlet line 33. The third changeover state thus describes the changeover state after a changeover of the main fluid flow HFS,

14A is a schematic detailed view of another one

Embodiment of a 3/2-way switch valve 3 in a first

Switched state shown. The 3/2-way switch valve 3 has one

Inlet line 31, a first outlet line 32 and a second outlet line 33.

A significant difference from that shown in Figures 13A to 13C

The exemplary embodiment consists in the fact that the changeover valve capillary 34 is not completely accommodated in the changeover valve housing 36, but only partially in the changeover valve housing 36.

In FIG. 14A, the main fluid flow HFS flows through the inlet line 31 via the changeover valve rotor 35 into the first outlet line 32. The depicted state is referred to as the first changeover state.

FIG. 14B shows the exemplary embodiment of the 3/2-way changeover valve 3 shown in FIG. 14A in a second changeover state. The changeover valve rotor 35 is in a position in which the main fluid flow HFS continues through the inlet line 31 via the changeover valve rotor 35 into the first one

Switch valve capillary 34 opens to the main fluid flow HFS, so that a pilot fluid flow PFS can flow through the switch valve capillary 34.

As a result, HFS occurs before the main fluid flow is switched

14C shows the exemplary embodiment of the 3/2-way changeover valve 3 shown in FIGS. 14A and 14B in a third changeover state. In this state, the main fluid flow HFS flows through the inlet line 31 via the changeover valve rotor 35 into the second outlet line 33. The third changeover state thus describes the changeover state after a changeover of the main fluid flow HFS.

At this point it should be pointed out that all the parts described above are seen on their own and in any combination, especially those in the

Details shown in the drawings, are claimed as essential to the invention, modifications thereof are familiar to the person skilled in the art.

Reference list

1 refrigerant circuit

2 air conditioning compressor

3 switching means (switching valve)

4 main condenser (main heat exchanger)

5 switchable condenser (switchable heat exchanger)

6 pressure adjustment means (pressure adjustment capillary)

7 evaporators

8 expansion valve (expansion capillary)

9 check valve

10 precoolers

11 control unit

12 pressure sensor

13 damping and / or insulation element and / or bypass line connection

31 Intake line of the changeover valve

32 first outlet line of the changeover valve

33 second outlet line of the changeover valve

34 changeover valve capillary (changeover valve capillary bore)

35 diverter valve rotor

36 changeover valve housing

HFS main fluid flow

PFS pilot fluid flow

Claims

Expectations

1. Refrigerant circuit (1), in particular for use in a vehicle, preferably a motor vehicle, comprising:

an air conditioning compressor (2),

a main capacitor (4),

at least one switchable capacitor (5), and

a switching means (3) which is designed to connect one or more of the connectable capacitors (5) to the refrigerant circuit (1)

switch on,

wherein a pressure adjustment means (6) is designed to adjust an internal pressure of the at least one connectable capacitor (5) to an internal pressure of the main capacitor (4).

2. Refrigerant circuit (1) according to claim 1, wherein the pressure equalization means (6) is suitable for heating the or the connectable capacitors (5) and / or the main condenser (4).

3. Refrigerant circuit (1) according to any one of the preceding claims, wherein the pressure equalization means (6) comprises an electrical heater, which is in particular switched on and off and / or designed to be controlled and / or regulated.

4. Refrigerant circuit (1) according to any one of the preceding claims, wherein the pressure equalization means (6) is suitable for heating one or more of the connectable capacitors (5) by inflow with waste heat from the main condenser (4).

5. refrigerant circuit (1) according to any one of the preceding claims, wherein the pressure equalization means (6) is suitable for heating one or more of the connectable condensers (5) by flow with preheated fresh air.

6. refrigerant circuit (1) according to any one of the preceding claims, further comprising at least one evaporator (7), at least one additional pressure changing means before, within and / or after the evaporator (7) with respect to a flow direction of the

Refrigerant circuit (1) is arranged, which is in particular designed to adapt an internal pressure of the evaporator (s) (7).

7. refrigerant circuit (1) according to any one of the preceding claims, wherein

At least one further section of the refrigerant circuit (1) can be temporarily disconnected and connected to the refrigerant circuit, wherein in particular the at least one further section is provided with at least one further pressure equalizer, which is preferably designed to apply an internal pressure of several sections to one another and / or to the Internal pressure of the

Main capacitor (4) and / or the switchable capacitor (5) to adjust.

8. refrigerant circuit (1) according to any one of the preceding claims, further comprising at least one throttle element (8), which is particularly controllable and / or regulatable, the throttle element (s) (8) preferably before, inside and / or after the evaporator (7) and / or the

Main capacitor (4) and / or the switchable capacitor (5) is arranged with respect to the flow direction of the refrigerant circuit (1), refrigerant circuit (1) according to one of the preceding claims, wherein furthermore a heat exchanger or phase separator is arranged upstream of the air conditioning compressor (2) with respect to the flow direction of the refrigerant circuit (1), 0, Refrigerant circuit (1) according to any one of the preceding claims, wherein the pressure adjustment means (6) comprises a pressure adjustment capillary through which the main condenser (4) with one or more of the switchable

Capacitors (5) and / or the connectable capacitors (5) can be fluidly connected to one another. 1, refrigerant circuit (1) according to claim 10, wherein the pressure adjustment capillary has a controllable shut-off valve and / or a check valve. , Refrigerant circuit (1) according to one of the preceding claims,

in particular according to one of claims 1 to 11, wherein the

Switching means (3), especially in combination with the

Pressure adjustment means (6) is arranged such that the or

connectable capacitors (5) can be / are connected in series to the main capacitor (4), the switching means (3), in particular in

Combination with the pressure adjustment means (6), preferably upstream with respect to the main capacitor (4) and the one or more connectable capacitors (5). , Refrigerant circuit (1) according to one of the preceding claims,

in particular according to one of claims 1 to 11, wherein the

Switching means (3), especially in combination with the

Pressure adjustment means (6) is arranged such that the or

connectable capacitors (5) can be connected in parallel to the main capacitor (4), the switching means (3), in particular in

Combination with the pressure adjustment means (6), preferably upstream with respect to the main capacitor (4) and the one or more connectable capacitors (5).

14. refrigerant circuit (1) according to any one of the preceding claims,

In particular according to claim 1, wherein the pressure adjustment means (6) can be controlled and / or regulated by a control or regulating unit (11).

15. refrigerant circuit (1) according to one of the preceding claims,

In particular according to claim 10, wherein the main capacitor (4) and the connectable capacitor (s) each comprise pressure sensors (12) which are designed to send measurement data of the pressure sensors (12) to the control or regulating unit (11) .

16. refrigerant circuit (1) according to any one of the preceding claims,

in particular according to claim 10, wherein in leads of

Main capacitor (4) and the one or more connectable capacitors (5) are each fitted with pressure sensors (12) which are designed to send measurement data from the pressure sensors (12) to the control or regulating unit (11).

17. refrigerant circuit (1) according to any one of the preceding claims,

in particular according to claim 1, wherein the pressure adjustment means (6) means for varying a waste heat flow in a waste air flow of the main condenser (4) and / or in or in the switchable

Has capacitors (5), in particular the means for varying the waste heat flow are pivotable louvre flaps.

18. The refrigerant circuit (1) according to one of the preceding claims, wherein the switching means (3) is designed as a switching valve, in particular a 3/2-way switching valve, which preferably enables a partially closed switching state in addition to an open and a closed switching state .

19. refrigerant circuit (1) according to one of the preceding claims,

in particular according to claim 18, wherein the changeover valve (3) has a pressure adjustment capillary (34) with which a fluid connection between a first outlet line (32) and a second one

Outlet line (33) of the changeover valve (3) can be produced.

20. refrigerant circuit (1) according to any one of the preceding claims,

in particular according to claim 19, wherein the pressure equalization capillary (34) has a valve which is suitable for opening and closing the pressure equalization capillary (34).

Refrigerant circuit (1) according to one of the preceding claims,

In particular according to claim 19, wherein the pressure adjustment capillary (34) is permanently open.

21. refrigerant circuit (1) according to one of the preceding claims,

in particular according to claim 18, wherein the switching valve (3)

Capillary bores (34) in a stator and / or a rotor of the

Switching valve (3).

22. Method for operating a refrigerant circuit according to one of the

Previous claims, wherein the main capacitor (4) is operated permanently actively and before and / or during connection of one or more of the switchable capacitors (5), the internal pressure of the switchable capacitor (s) (5) to the internal pressure of the

Main capacitor (4) is adjusted,

23. The method according to claim 22, wherein when connecting one or more of the connectable capacitors (5), first a pilot fluid flow (PFS) through the pressure equalization capillary (6, 34) and / or the capillary bores of the changeover valve (3) for equalizing the internal pressure of the or the connectable capacitors (5) to the internal pressure of the

Main capacitor (4) flows.

24. The method according to claim 22 or 23, wherein a speed and / or a mass flow of the air conditioning compressor (2) is determined before and / or during the connection, the air conditioning compressor (2) when the speed and / or the mass flow is a very small one Value is the

is preferably equal to zero, is controlled such that the speed and / or the mass flow is regulated to this very small value, which is preferably equal to zero.

25. Vehicle, in particular motor vehicle, comprising a

Refrigerant circuit according to one of claims 1 to 21, which is operated in particular by a method according to one of claims 22 to 24.